The 50-150mm zoom is a useful lens in its own right. It would be nice if it were slightly smaller and lighter as it's noticeably larger than its predecessor. It's actually almost identical in size to the 70-200mm f/2.8 from Sigma, but as it stands it feels robust and durable. The AF system generally performed well but occasionally hunted at 150mm. That, and minor colour fringing, aside this is...

Sigma has a habit of identifying shortcomings in the lens offerings by other camera manufacturers and exploiting them: in 2006, with the introduction of the first 50-150mm /2.8 DC, it managed a coup, offering a 70-200mm experience for the APS-C camera. Sigma has certainly managed to improve on the initial and subsequent redesign of that lens, in the current optically-stabilized implementation....